Long lines, fewer X-ray machines, planes stuck on US runways and doubts about air traffic control: look forward to travel misery this summer if budget-slashing sequestration takes effect Friday. Industry experts say passengers won\'t notice immediate change if President Barack Obama signs off on $85 billion of cuts to the federal budget, because labor laws mean furloughed airport workers have to be given 30 days notice. But don\'t get too comfortable. By mid-April staffing gaps will appear, with employees laid off an estimated one day every other week through the end of the fiscal year in September, said Dan Stohr, spokesman for the Aerospace Industries Association, a trade group. \"By late May, early June, when the travel season really kicks off, that\'s when you\'re going to see the impacts,\" Stohr told AFP. Cuts will eat into the ranks of all the people who make airports tick: TSA inspectors manning those X-ray machines, customs officers at passport desks, and FAA employees like those in the control towers. Control towers at about 100 smaller regional airports, ranging from Mobile, Alabama, to Niagara Falls, New York, are likely to be shut down altogether. Another 60 in mid-sized cities such as Jacksonville, Florida, and Sacramento, California, could have their overnight shifts eliminated. Although the nation\'s biggest hubs are likely to be protected as far as possible, an ongoing sequestration means they won\'t be spared, with monster lines at customs and other grief for already hassled travelers. \"At our busiest airports..., peak wait times, which can reach over two hours, could easily grow to four hours or more,\" Homeland Security Secretary Janet Napolitano said. Experts fear there could be wider implications. The National Air Traffic Controllers Association issued a stark warning, calling the budget cuts \"detrimental to the National Airspace System, as well as to the nation\'s fragile economy.\" \"All users and operators of the NAS (air travel system), including travelers, general aviation pilots, airlines, businesses and the military will feel the effects.\" Stohr said that a shortage of inspectors means new planes can\'t be certified and delivered, which \"impacts our industry directly.\" Even longer term, Stohr warned of putting the brakes on a huge, ongoing reform of the country\'s air traffic control system from a ground based to satellite system. Lengthy sequestration conditions could \"set it back by several years,\" he said. Some argue that the dire predictions are more the result of politics than anything else. While Obama accuses Republicans of refusing to hash out a deal, they in turn claim the furloughs are being targeted at the wrong places. Senator John Thune and Representatives Bill Schuster and Frank LoBiondo issued a joint statement accusing the administration of \"creating alarm\" and exaggerating the need for cutting air traffic controllers. Boyd Group International, an aviation consultancy, attacked the government for being ready to \"torpedo the US economy if they don\'t get their way.\" They\'ll \"close control towers at dozens of other airports, too. And they will slash the air transportation infrastructure on which the nation\'s economy depends.\" Henry Harteveldt, a travel industry analyst with the Hudson Crossing consultancy, said \"a massive amount of uncertainty\" is the rule for now. \"The politicians have been very good about stirring up the drama, but less helpful about providing specifics about what will happen and what to expect,\" he told AFP. \"What\'s really unfortunate about this is that in the next couple weeks you start to have schools and universities go into spring break and you have people starting to plan their summer vacation,\" he said. \"If there\'s a lot of chaos, if people are unhappy with this, I\'m afraid there could be a negative effect on (the) air travel,\" industry.